Adapted from Fenghuang Qi's novel - The Song of the Bronze Bird in Chang'an - Zhu Yan, a concubine in the Zhu Mansion, studied under the supervision of the Chief Prison Superintendent of the Ministry of Punishment since she was a child. She has acquired the skills to solve cases and can find the answers hidden in the physical evidence through clues.Zhu Yan was admitted to the Ministry of Justice and became a female officer, determined to find out the real murderer and uphold justice.However, because the third sister escaped from the marriage granted by the Empress Dowager, in order to save her family, Zhu Yan had to marry her sister and married Lu Li, the chief minister of the Imperial Guard House.Bizarre cases occurred frequently in Beijing. Zhu Yan and Lu Li worked together to solve many unsolved cases, and their relationship gradually heated up during the process of solving the cases.Zhu Yan, Lu Li and other partners worked together to uncover the shocking conspiracy and protect the peace and justice of Xiang'an City.